Furnace clean and tune. Cycled system. Checked heat exchanger, found all three chambers are rusted and corroded. No visible cracks found with camera. Checked, removed, and cleaned burners and flame sensor. Found igniter/flame rod worn. Flame sensor is corroded. Igniter tested low, but within normal range. Checked and tightened electrical connections and clamps. Cleared drain lines. Checked and adjusted gas pressures to maximize efficiency. Found ventor motor bearings are showing signs of getting worn. Preformed combustion test and found levels in normal range. No CO found in airstream. Average life expectancy for this unit is 14 years. This system is 17 years old and showing signs of getting worn. System operating normal at this time, but failure is expected. Tested and checked humidifier. Ok Fireplace clean and tune. Cycled system. Removed and cleaned glass. Checked and cleaned logs. Found logs were incorrectly placed in unit. Cleaned walls and under unit. Cleaned ignition system. Pla